f46851e627
(Upstream commit 7771bdbbfd3d6f204631b6fd9e1bbc30cd15918e). Use after scope bugs detector seems to be almost entirely useless for the linux kernel. It exists over two years, but I've seen only one valid bug so far [1]. And the bug was fixed before it has been reported. There were some other use-after-scope reports, but they were false-positives due to different reasons like incompatibility with structleak plugin. This feature significantly increases stack usage, especially with GCC < 9 version, and causes a 32K stack overflow. It probably adds performance penalty too. Given all that, let's remove use-after-scope detector entirely. While preparing this patch I've noticed that we mistakenly enable use-after-scope detection for clang compiler regardless of CONFIG_KASAN_EXTRA setting. This is also fixed now. [1] http://lkml.kernel.org/r/<20171129052106.rhgbjhhis53hkgfn@wfg-t540p.sh.intel.com> Link: http://lkml.kernel.org/r/20190111185842.13978-1-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Will Deacon <will.deacon@arm.com> [arm64] Cc: Qian Cai <cai@lca.pw> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Change-Id: I00d869a5e287e3e198950b78ad17bd6ff6a51595 Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Bug: 128674696
51 lines
1.4 KiB
Text
51 lines
1.4 KiB
Text
# SPDX-License-Identifier: GPL-2.0
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ifdef CONFIG_KASAN_GENERIC
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ifdef CONFIG_KASAN_INLINE
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call_threshold := 10000
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else
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call_threshold := 0
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endif
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KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
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CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
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cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1)))
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# -fasan-shadow-offset fails without -fsanitize
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CFLAGS_KASAN_SHADOW := $(call cc-option, -fsanitize=kernel-address \
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-fasan-shadow-offset=$(KASAN_SHADOW_OFFSET), \
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$(call cc-option, -fsanitize=kernel-address \
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-mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)))
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ifeq ($(strip $(CFLAGS_KASAN_SHADOW)),)
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CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
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else
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# Now add all the compiler specific options that are valid standalone
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CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \
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$(call cc-param,asan-globals=1) \
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$(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
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$(call cc-param,asan-stack=$(CONFIG_KASAN_STACK)) \
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$(call cc-param,asan-instrument-allocas=1)
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endif
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endif # CONFIG_KASAN_GENERIC
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ifdef CONFIG_KASAN_SW_TAGS
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ifdef CONFIG_KASAN_INLINE
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instrumentation_flags := -mllvm -hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)
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else
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instrumentation_flags := -mllvm -hwasan-instrument-with-calls=1
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endif
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CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
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-mllvm -hwasan-instrument-stack=0 \
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$(instrumentation_flags)
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endif # CONFIG_KASAN_SW_TAGS
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ifdef CONFIG_KASAN
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CFLAGS_KASAN_NOSANITIZE := -fno-builtin
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endif
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